Air-freshener evaporator



May 18 1954 R. CHANDLER 2,678,810

AIR-FRESHENER vAPoRAToR Filed July 30, 1951 BY Fay (hand/ff gTmR/VEY Patented May 18, 17954 UNITEDl STAT S PATENT OFFICE 1 Claim.

This invention relates to an air-freshener evaporator for use in an air-conditioning or ventilating installation which provides a forced draft of Ventilating air.

A recent commercial development in air conditioning and ventilation is the increasing application of liquid and vaporous air fresheners by disersion in Ventilating air for the control of the quality oi the air. These air fresheners are of various types and have for their main function the elimination of objectionable odors from and the addition of desirable odors to Ventilating air in spaces occupied by human beings; they may also have other functions such as sterilization.

A few devices have been developed for evaporating such air iresheners in Ventilating air. While the problem of designing such evaporators is in some respects similar to that of designing distributors of water mist or vapor ior humidifying air, it has one fundamental difference: whereas relatively large amounts of water must be dispersed for effective humidication, the amount of air freshener to be dispersed in a given volume of air is limited to a minute amount, and this must be accurately metered. It is more dinicult to distribute an accurately dosed relatively minute amount of material evenly in a large amount oi medium than to measure and distribute relatively large amounts of material in large amounts of medium.

lt is one object of my invention to provide a device for eiiiciently distributing accurately dosed small amounts of air freshener in large amounts of Ventilating air as required.

It is another object of my invention to provide a device of this kind characterized by the utmost simplicity, smallness, flexibility and reliability.

It is a further object of my invention to provide a device of this kind that operates without requiring an extraneous power source such as an electric motor, thus reducing fire hazards.

It is a still further object of my invention to provide a device of this kind that may readily be installed in existing air-conditioning or ventilating systems and units without modification of the systems or units.

My device comprises the following main elements: (A) a pan to contain the air freshener in liquid form; (B) a source of air freshener; (C) a constant level device connected with the source and the pan to maintain a constant level of air freshener in the latter; (D) a horizontal shaft rotatably mounted over the pan and at one end extending beyond the pan; (E) discs iixedly mounted on the shaft and adapted to dip into the liquid in the pan; (F) a wind wheel xedly attached to the end of the shaft extending beyond the pan; (G) a fixed shield covering approximately half oi the wind wheel; and (H) an adjustable hood or hoods adapted to be so positioned as to screen a desired segment of the discs or wind wheel or both to reduce and control the rate of evaporation.

The device is advantageously made of stainless steel; the discs (E) are round, smooth and nonserrated to offer minimum resistance in passing through the liquid air ireshener. The whole device is of small enough size to be easily handled and placed in an air duct of an air-conditioning or Ventilating system or unit. I provide an outside bottle or small tank (B) of air-freshener liquid connected with pan (A) through a conventional constant-level device (C) Working on the student-lamp principle to maintain a constant level of liquid in the pan.

My device is a small evaporator which will operate eiiiciently and silently, and may be inserted into the duct of an air conditioning system or located anywhere else in a Ventilating system where air will pass over the evaporator with sufficient velocity to activate the rotor. The same air which activates the rotor carries the airfreshening vapors throughout the premises.

Aside from being small enough and sufficiently flexible to be located in practically any part of a system, one or more evaporators may be mounted side by side ii the evaporating capacity of the single unit is not sufcient, so that virtually any practical volume of air may be treated to meet any demand.

The facts that the evaporator requires no electrical connection and is so small as to produce virtually no back pressure in the air stream, as well as the fact that it can be adjusted as to vapor output, permit the use of extra evaporators as boosters in certain sections of an air conditioning system serving premises with an extra high odor level.

Owing to the small size and method of operation of my evaporator it is also adapted to be hung on the front guard of a pedestal or other type electric fan where air freshening and deodorizing of the premises is desired as well as ventilation.

One embodiment of my invention is illustrated in the following description and drawings, but these are intended to be illustrative only and not to limit my invention, which is defined in the appended claims.

In the drawings Fig. 1 is a perspective view of my device; Fig. 2 is a diagrammatic transverse section on plane 2-2 of Fig. l; Fig. 3 illustrates my device mounted in the discharge chamber of an air-conditioning unit; Fig. 4 is a view of my device from the wind wheel end with an alternative regulating means; and Fig. 5 is a section on line 5-5 of Fig. 1,

The illustrated embodiment comprises a shallow rectangular pan I provided with a liquid inlet 2 and a cover 3. On one end of the pan is spot- Welded shield 4 on which is mounted bracket 5 provided with bearing 6. A bracket 'I provided with bearing B is welded to the opposite end of pan I. A shaft 9 is rotatably mounted on bearings G and 8 just below cover 3 which is provided with a plurality of slots I6. Fixedly positioned on the portion of shaft 9 above pan I is a plurality of round, smooth, non-serrated discs I I extending above cover 3 through slots ID and extending downwards into air-freshener liquid I2. On the end of shaft 9 extending beyond pan I and supported by bearing 6 is xedly mounted a wind wheel I 3 provided with vanes Irl; substantially half the wind wheel extends down into and is screened by shield 4 to insure its rotating.

Upturned flanges I5 and I5 are welded on top of cover 3 at opposite ends and serve to support hood IS, pivoted at Il. Hood IB consists of two sections i8 and i9, each a hollow cylindrical segment, section I9 being slightly larger in order to receive section I8 when the hood is folded. One longitudinal edge of section I8 is provided with out-turned ange 2i), adapted to engage in-turned flange 2l on a longitudinal edge of section IS when the hood is raised. A handle 22 is welded to section I 8 to facilitate its manipulation and friction springs 23 and Z4, respectively welded to section i9 and bearing on section I8 and welded to cover 3 and bearing on section I9, retain the hood in any desired position.

My device is conveniently located in the discharge chamber of an air-conditioner unit 25 on shelf 26 or at any point in the Ventilating air stream of an air conditioning system where there is suicient air velocity to activate the wind wheel. It is provided with a constant level device of the student-lamp type consisting of an inverted bottle or tank 27 dipping into a constant level chamber 28 connected with pan I by inlet pipe 2. In unit 25 conditioned air is drawn by centrifugal fan 29 from the lower part of the l unit as indicated by arrows a, forced through opening 36 into the top of the unit over my airfreshener dispenser and exhausted through louvers SI as indicated by arrows b.

The air current impinging on the upper half of wind wheel I3 causes it to rotate and thus to revolve shaft 9 and discs l. The discs, dipping into the liquid air freshener, become coated with a lm of the liquid which is continually exposed to the circulating air. The air freshener evaporates from the ilrn on the upper segments of the discs exposed to the air current which carries the vapors throughout the premises being treated and the lm of liquid is continually renewed as the discs rotate.

For given conditions of type of air freshener, temperature, air velocity and rotational velocity, the rate of evaporation of the air freshener will be approximately proportional to the disc area exposed to the air stream. It will be clear that this exposed area can readily be controlled by positioning the hood I6 to screen a larger or smaller segment of discs II from air current b. With a device of the kind described having I0 discs 3 inches in diamter, I have found it easy to regulate the evaporation rate of a commercial air freshener from 1-0- ounce to 1 ounce per hour at will by suitably positioning hood I6. For any given set of conditions the position of the hood may be calibrated for various desired rates of evaporation and the calibrations indicated by index marks on the ends of hood sections i8 and I9 as shown at 32.

An alternative method of regulating evaporation rate is by varying the speed of rotation of shaft 9 and discs II. This may be done by partially screening the upper portion of the wind wheel I3 as shown in Fig. 4. An adjustable fiat shield 3S is provided (perpendicular to the plane of the drawing) having slotted ilange 34 on its outboard edge. This is adjustably secured to shield 4 by two nuts and bolts 35. Raising or lowering shield 33 and securing it by bolts 35 effectively regulates the windage on wind wheel I3 to cause it to rotate with less or greater velocity as desired.

A further alternative method of regulating the speed of rotation of the discs is by tightening the bearing screw 8', thus slowing down the rotation.

I claim:

A self-contained air-freshener evaporator adapted to be positioned in an air stream of an air-conditioner or Ventilating unit or system and to be operated solely by the iiow of said air stream without connection to other power source, said evaporator comprising in combination: a fiat oblong pan adapted to contain a layer of liquid air freshener, a storage container` for air freshener connected to the pan by a constantlevel device adapted to maintain the layer of liquid air freshener at a substantially constant height in the pan, a horizontal shaft rotatably mounted over the pan and having one end extending beyond the pan, smooth circular discs xedly mounted on the portion of the shaft over the pan and adapted to dip into the liquid in the pan, a cover over the pan having slots through which the discs project, a wind wheel with vanes xedly attached to the end of the shaft extending beyond the pan, said wind wheel, discs and shaft constituting a rotating unit, a fixed shield screening approximately half of the wind wheel on one side of the shaft, whereby the air stream impinging on the unscreened half of the Wind wheel causes it and the shaft and discs to rotate thus causing the discs to carry films of liquid from the pan to the space above the slotted coverl where they are exposed to the air stream, and an adjustable hood in the form of a segment of a cylinder pivoted near the axis of the shaft and adjustably surrounding a portion of the rotating unit exposed to the air stream, whereby the rate of evaporation of air freshener into the air stream can be regulated.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 902,622 Subert Nov. 3, 1908 1,285,101 Foster Nov. l0, 1913 2,136,634 Peoples Nov. 15, 1938 2,344,536 Coey et al. Mar. 2l, 1944 

